diff --git a/perl/array.pl b/perl/array.pl
new file mode 100644
index 0000000..a556fa6
--- /dev/null
+++ b/perl/array.pl
@@ -0,0 +1,11 @@
+#!/usr/bin/perl
+
+@disk_cap = (50, 30, 40, 'fifty five',66,80,90);
+$size_of_array_disk_cap = @disk_cap;
+$max_index=@disk_cap - 1;
+@cards = ("csc01", "xcc360g", "xcc80g");
+@line_cards = qw(cef5 cef4c xa10g);
+print "disk_cap = @disk_cap\n";
+print "disk_cap[0] = $disk_cap[0]\n";
+print "line_cards[0] = $cards[0] cards[-1] = $cards[-1]\n";
+print "size of array \@disk_cap = $size_of_array_disk_cap max_index = $max_index\n";
\ No newline at end of file
diff --git a/perl/wiki b/perl/wiki
index e246d22..5021632 100644
--- a/perl/wiki
+++ b/perl/wiki
@@ -97,4 +97,224 @@
 
     exception:
     '#!/usr/bin/perl' Shabang is not comment. It just tell
-    the bash that its a perl script.    
\ No newline at end of file
+    the bash that its a perl script.
+
+-> Whitespace:
+
+    Like C, perl script does not care about whitespaces, unless they 
+    are inside the quoted strings, then they would be printed as it is.
+
+-> Single/double quote:
+
+    Only double quotes expand variable and special characters such as
+    newlines \n.
+
+    $a = 10;
+    print "Value of a = $a\n"
+    print 'Value of a = $a\n'
+    
+    Output:
+    Value of a = 10
+    Value of a = $a\n$
+
+    This is behaviour is similar to shell scripts.
+
+-> Multi line strings
+
+    $a = 10;
+    $multiline_str = <<"END_OF_LINE_DELIMITER";
+    This is the syntax for multi line string and will continue until
+    it encounters a END_OF_LINE_DELIMITER in the first line.
+    Also see the effect of single and double quote a=$a
+    END_OF_LINE_DELIMITER
+
+    print "$multiline_str\n";
+
+    Output:
+    This is the syntax of multi line string and will continute until
+    it encounters a END_OF_LIN_DELIMITER in the first line.
+    Also see the effect of single and double quote a=10
+
+    In case of : $multiline_str = <<‘END_OF_LINE_DELIMETER’;
+ 
+    Output would differ value of a will not expand. So a=$a will come at the end.
+    
+    • Escape Char : Perl uses the backslash (\) as escape character .
+    Ex: print “\$multiline_str\n";
+    
+    Output : $multiline_str
+    
+    • Identifiers : Perl does not allow punctuation characters such as @, $, and %
+    within identifiers. Perl is a case sensitive programming language. So $a & $A
+    are different.
+
+-> Variable(Scalar):
+
+    Mainly perl have three type of variable:
+        * Scalar (Denoted by $ in the starting)
+        * Array
+        * Hashmap
+
+    If strict is being used : This is mandatory to declare a variable before we use it if
+                                we use use strict statement in our script.
+                                
+                                Syntax:
+                                use strict
+        
+        • Scalar : defined by $ at the start.
+                    
+                    Ex:
+                    #!/usr/bin/perl
+                    $threads= 2; # An integer assignment : a numerical scalar
+                    $compilation_dir = “/home/techie/mirror/$threads"; # A string scalar double quoted
+                    $compilation_dir2 = ‘/home/techie/mirror/$threads’; # A string scalar in single quote
+                    print “threads = $threads\n";
+                    print “compilation_dir = $compilation_dir\n";
+                    print “compilation_dir2 = $compilation_dir2\n";
+
+                    Output :
+                    threads = 2
+                    compilation_dir = /home/techie/mirror/2
+                    compilation_dir2 = /home/techie/mirror/$threads
+
+    ###Scaler Operations####
+
+        #!/usr/bin/perl
+        $threads= 2 + 4; # adds two numbers
+        $image_name = “csc01_“ . “mips.img” ; # concatenate 2 strings
+        $final_with_prefix= $threads . “_” . $image_name ; # concatenate number
+        with string
+        print “threads = $threads\n";
+        print “image_name = $image_name\n";
+        print “final_with_prefix = $final_with_prefix \n";
+
+        Output :
+        threads = 6
+        image_name = csc01_mips.img
+        final_with_prefix = 6_csc01_mips.img
+
+
+-> Multiline String and special literals:
+
+        Special literals can’t be expanded.
+        
+        $string = 'This is a
+        multiline string with special literals ’ . __PACKAGE__ . “_” . __FILE__ . “_” .
+        __LINE__ . “__LINE__”;
+        print "$string\n";
+        Output : This is a
+        multiline string with special literals tUtils_train.pl_55__LINE__
+
+
+-> Variable(array):
+
+    Arrays, size of array & max index : Defined by @ at start.
+    
+    #!/usr/bin/perl
+    @disk_cap = (50, 30, 40, ’fifty five’,66,80,90);
+    $size_of_array_disk_cap = @disk_cap
+    $max_index=@disk_cap - 1
+    @cards = (”csc01", ”xcc360g", ”xcc80g");
+    @line_cards = qw(cef5 cef4c xa10g)
+    print “disk_cap = @disk_cap\n";
+    print “disk_cap[0] = $disk_cap[0]\n";
+    print “line_cards[0] = $cards[0] cards[-1] = $cards[-1]\n";
+    print “size of array \@disk_cap = $size_of_array_disk_cap max_index =
+    $max_index\n";
+
+    Output :
+    disk_cap = 50 30 40 fifty five 66 80 90
+    disk_cap[0] = 50
+    line_cards[0] = cef5 cards[-1] = xcc80g
+    size of array @disk_cap = 7 max_index = 6
+
+-> Sequential Number arrays:
+    
+    @var_20=(10..20); print "@var_20\n";
+    10 11 12 13 14 15 16 17 18 19 20
+
+    Similarly, in shell we use:
+    seq 1 5
+    
+    Output:
+    1 2 3 4 5
+
+-> Operation on arrays:
+
+    * push:
+        Syntax:
+        push(@array, value)
+
+        Example:
+        @cards = (”csc01", ”xcc360g", ”xcc80g");
+        print "2. \@cards = @cards\n";
+        #add one element at the end of the array
+        push(@cards, "csc02");
+        print "2. \@cards = @cards\n";
+
+        Output:
+        2. @cards = csc01 xcc360g xcc80g
+        2. @cards = csc01 xcc360g xcc80g csc02
+
+    * unshift:
+        Syntax:
+        unshift(@cards, "xcc80g")
+
+        Example:
+        @cards = qw(csc01 cef5 xcc360g);
+        print "2. \@cards = @cards\n"
+        print "       push csc02\n"
+        #add one element at the start of the array
+        unshift(@cards, "xcc80g");
+        print "3. \@cards = @cards\n";
+
+    * pop:
+        Syntax:
+        pop(@array);
+
+        Example:
+        @cards = qw(csc01 cef5 xcc360g);
+        print "        pop\n";
+        # remove one element from the last of the array
+        pop(@cards);
+        print "4. \@cards = @cards\n"
+
+
+    * shift:
+        Syntax:
+        shift(@array)
+
+        Example:
+        @cards = qw(csc01 cef5 xcc360g);
+        print "        shift\n";
+        # remove one element from the beginning of the array
+        shift(@cards);
+        print "5. \@cards = @cards\n";
+
+
+-> Slicing Array elements:
+
+        Syntax:
+        @array[2,4];
+        or @array[1..4];
+
+        Example:
+        @cards = qw(csc01 cef5 xcc360g cef8 cef4c);
+        print "==========Slicing Array elements============"
+        @group1 = @cards[2,4];
+        print "\@group1 : @group1\n";
+        @group2 = @cards[1..4];
+        print "\@group2 : @groups\n";
+
+        Output:
+        ==============Slicing Array elements================
+        @group1 : xcc360g cef4c
+        @group2 : cef5 xcc360g cef8 cef4c
+
+
+
+-> my keyword:
+
+    my keyword is used in perl to limit the scope of variable
+    to particular function or any scope where it is defined.
+